Journal of Natural P&s Val. 57, NO.6,Pp. 784-790,JUW 1994
784
MINOR TRITERPENOIDS FROM THE MEDITERRANEAN SPONGE, RASPACZONA AC ULEATA G u m CIhLINO, A N N A U
N O , *
ENRICOTRIVELLONE,
lstitutopw la Chimica di Molerole di Interesse Biologico del CNR Via Toirrno 6, 80072 Arro Felice (NA), Italy and MARIA URIZ Centm GEstudios Avanzados, Cam?de Santa Barbara, I7300 Blanes, Gerona,Spain
ABsmcr.-Eight new minor triterpenoids have been characterized from a lipid-soluble extract of Raspaciona aruleuta. All are based on the same carbon skeleton as raspacionin 117.The fidl assignment of all 'Hand 13C-nmrresonances has led to the rationalization of the effects of certain substituents on the chemical shifcs of atoms in the perhydrobenzoxepine system.
Raspacionin {l]and raspacionins A 127, and B 131 are three terpenoids recently found in the encrusting red sponge, Raspaciona aculeuta Johnston (family Raspailiidae) (1-3). Their structures have been elucidated by X-ray analysis and by extensive nmr investigations. Their absolute stereochemistry has been suggested either by applying high-resolution 'H nmr (2,4) to the Mosher method (5,6), as successfully proposed for sipholenol A 147 by Kakisawa's group (7-lo), or by comparison of cd spectra (3). In this communication we now report the structural characterization of a further eight 15-12} minor components ofRaspacionaaculeuta,all based on the same triterpenoid skeleton as raspacionin 117. The structures of the new raspacionins display different functionalizations at carbons 4, 10, 15, and 21. The full nmr characterization of 5-12 has revealed that some shifts of the substituents are diagnostic for both ring location and stereochemical orientation. The only previous triterpenoids related to raspacionins,besides those from Raspaciona aculeuta, have been those from the sponge Siphonocalina siphonella (11-15) and, more recently, from the South African purple-brown fan sponge Axinella weltnwi (16). RESULTS AND DISCUSSION The lipid-soluble extract from Raspaciona aculeuta was submitted to the usual workup (2,3) yielding, along with 1 and a mixture of 2 and 3, a more polar fraction (Rf0.27, petroleum ether-Et,O, 3:7) that was purified by hplc (Spherisorb Silica column, nhexane-EtOAc, 7:3) giving seven main fractions which, after further hplc purification, yielded eight pure isolates 15-12]. The structural characterization of the products is reported herein, starting from compound 5 , which was most closely related to raspacionin El],and then reporting the other metabolites according to their chemical affinity with 1. 2 1-Deacetyl-raspacionin 151 is an optically active compound with elemental composition C3,H,,06 determined by hreims on the fragment ion peak at mlz 474.3698 IM-HOAc}+ (C,,H,,O, requires 474.3709). The 'H-nmr spectrum of 5 was almost identical to that of raspacionin 117;diagnostic differences were the chemical shift of H21 (6 3.82; 6 4.97 for 1)and the absence of the acetyl methyl singlet at 6 2.17. All 'Hand l3C-nrnrresonances (Tables 1 and 2) were assigned by 1D and 2D nmr experiments (DEPT, 'H-13C HETCOR, 'H-'H COSY). By comparing the nmr data of 5 with those of raspacionin 117, it was observed that the absence of an acetyl group at C-21 induces, besides the expected shifts for the atoms near C-2 1, two 'H-nmr downfield shifts for H14 (6 0.83; 6 0.74 for 1) and H-18 (6 3.55; 6 3.41 for 1).Methanolysis of 1 yielded a compound identical in all aspects to 5 .
p
Cimino et ai. : Triterpenoids from Raspaciona
June 19941
7
:
785
OH OAC
2
B H e (0 ,!I
%-
12
2D
28
1 R=Ac 5 R=H
3
6 R , = H ; R,=H; R,=Ac 10 R, =Ac; R,=Ac; R , = H
7 R,=H;R,=Ac 8 R,=H;R,=H 9 R,=Ac;R,=H
11 R , = A c ; R , = H 12 R, = H ; R,=Ac
10-Acetoxy-21-deacetyl-28-hydroraspacionin161, exhibited a molecular formula of C34H5808, deduced from hreims at mlz 474.3684 (main mass fragment peak, [M-~HOAC]'; C30H1004 requires 474.3709). The 'H-nrnr spectrum of 6 was differentiated from that of 1 by the absence of the exomethylene protons and by the presence of two singlet methyls at 6 1.89 (OCOCH,-lO) and 6 1.48 ( H -28), consistent with a different substitution pattern at carbons 10 and 28 in 6. The 13C-nmr resonance of C28 at 6 19.71 supported an axial orientation of this methyl functionality. The stereochemistry at C-10 was differentiated from that at C-15 by a series of diagnostic shifts. Thus, the equatorial orientation of the acetoxy group at C-10 induced 'H-nmr upfield shifts for the equatorial H-9 (6 2.63; H-16 eq 6 2.78) and for H,-25 (6 0.83; H,32 6 0.96) and downfield shifts for C-8 (6 30.32; C-17 6 26.62), C-9 (6 35.49; C-16 6 33.06), and H-11 (6 1.53; H-14 6 0.80).
Wol. 57, No. 6
Journal of Natural Products
786
"C-Nmr Chemical Shifts of Ra! rionin 111 and Related Trite TABLE 1. -
- -
Carbon c-2 . . . . . . . . .
c-7 . . . . . . . . . c-8 . . . . . . . . . c-9 . . . . . . . . . c-10 c-11 . . . . . . . . c-12 . . . . . . . . C-13 . . . , . . . . C-14 . . . . . . . . C-15 . . . . . . . . C-16 . . . . . . . . C-17 . . . . . . . . c-18 c-20 . . . . . . . . c-21 . . . . . . . . c-22 C-23 . . . . . . . . C-24 . . . . . . . . c-25 C-26 . . . . . . . . C-27 . . . . . . . . c-28 . . , . . , . . C-29 . . . . . . . . C-30 . . . . . . . . C-31 . . . . . . . . C-32 . . . . . . . . OCOCH,-4 . . . OCOCH3-10 . . OCOCH,-15 . . OCOCH,-21 , , OCOCH,4 . . . OCOCH,-lO . . OCOCH3-15 . . OCOCH3-21 . .
6
7
8
9
10
42.82* 34.24** 25.32 76.W 77.88 75.84 30.32 35.49 87.13 56.06 28.17 29.10 57.99 84.25 33.06 26.62 76.21 77.88 77.03' 25.32 34.63** 42.96* 13.16 28.9021.46 19.71 24.67 21.46 29.00" 12.92
42.16 40.27 35.07 217.51 82.66 80.70 30.24 35.26 86.40 55.65 27.97 29.02 57.95 84.11 33.03 26.60 76.10 77.91 76.96 25.25 34.32 42.81 12.53 26.45 20.48 19.85 24.73 21.43 28.96 12.85
42.14 40.14 35.02 217.56 82.65 80.68 30.37 35.24 86.27 55.68 27.96 28.87 55.68 72.20 39.25 26.54 76.25 77.76 77.17 25.09 34.12 42.55 12.49 26.42 20.45 19.69 30.31 21.31 29.00 12.93
42.14 40.27 35.06 217.30 82.64 80.63 30.39 35.29 86.29 55.87 27.95 29.02 55.87 72.08 39.37 26.43 76.62 nd' 79.07 23.02 35.42 42.45 12.65 26.43 20.46 19.71 30.39 21.49 28.96 12.90
70.09 69.93
170.06 170.00
170.20
170.12
42.85 35.89* 23.20*' 78.76 77.47 76.16 30.50 35.38 86.92 56.19 28.00 29.05' 56.02 72.25 39.41 26.43 76.64 77.47 79.02 23.10*' 35.49* 42.45 13.27 29.00" 21.5319.72 30.41 21.48" 28.81' 13.09 170.23 170.23
5 - 1
43.37b 33.90 26.10 77.00 77.57 76.01 33.02 35.74 147.17 53.65 27.59 25.48 58.18 83.81 33.21 26.59 76.74 77.33 79.14 23.08 35.32 42.80b 12.20 29.11 21.23 107.38 25.26 21.56 28.96 12.81
-
170.16 170.16
43.44 33.85 26.05 77.06 77.56 76.03 33.09 35.76 147.28 54.00 27.97 25.88 58.08 83.92 33.09 26.73 76.29 77.87 77.06 25.34 34.19 43.06 12.13 29.12 21.23 107.36 25.25 2 1.46 29.04 12.81
-
170.29
-
-
-
-
-
22.51 21.23
22.52
-
-
22.88 22.40
-
-
-
-
-
-
-
-
22.82 22.38
23.05
-
-
-
170.12
-
23.08
170.23 21.29 23.20
21.28
21.29
-
-
-
: n e 5-12.' 11 42.14 40.30* 34.98 nd'
82.68 80.60 30.35 35.25 86.29 55.58 27.94 28.83 55.52 72.00 39.27 26.40 81.03 82.42 nd' 34.98 39.88* 41.84 12.50 26.57 20.46 19.77 30.52 20.47 26.40 12.20
nd' -
-
12 42.03 41.32. 35.03** 217.78' 82.63 80.97 26.45 40.00 73.22 57.93 28.76 29.79 57.93 83.58 32.91 30.12 80.97 82.57 217.55' 35.09** 40.49* 41.75 12.25 26.48 20.46 23.54 24.48 20.46 26.45 12.25
-
170.09
-
-
-
23.07
-
-
22.53
-
'CDCI,; Bruker AMX-500 spectrometer. Chemical shifts referenced to CJXI, at 77.00 pprn. %ese d u e s were erroneously reponed (1) inverted. 'Nd=Not detected. ****'Values with the same superscripts m a y be interchanged.
Surprisingly, the resonance of C-13 (6 29.10) was shifted downfield almost 4 ppm from the values recorded for 1 (6 25.48) and 5 (6 25.88). It is likely that a dominant conformation displaying a 6 effect between C-13 and the substituent at C-10 can explain this apparent anomaly. All the 'H- and 13C-nmrresonance assignments were confirmed by 2D experiments (Tables 1 and 2). 10-Acetoxy-21deacetyl-4-oxo-28-hydroraspacionin exhibited an elemental composition of CMI-$08, based on hreims of the ion fragment peak at mlz 5 14.3645 [M-HOAc-H,O] ; 514.3658 calcd for C3,Hj20,. The spectral data of 7 were compared with those of 6 revealing an additional C-nmr resonance at 6 217.5 1 that, along with the absence of one of the two carbinol protons at 6 3.82, supported the presence in 7 of a carbonyl group at C-4. Moreover, comparison with 6 revealed that the different functionalitation at C-4 induced some diagnostic shifts for all protons and carbons of the seven-membered ring and, in addition, H-7 and H-11 were shifted upfield to 6 2.97 (6 3.63 for 6 )and 6 1.46 (6 1.53 for 6),respectively. All 'H- and 13Cnmr resonances were confirmed by 2D experiments (Tables 1 and 2). 10-Acetoxy- 15,2 1-dideacety1-4-0~0-28-hydroraspacionin IS] possessed the molecular formula C32H,407,deduced by hreims at mlz 472.3535 {M-HOAc-H,O]+,
June 19941
Cimino et al. : Triterpenoids from Raspacionu
787
TABLE 2. 'H-Nmr Chemical Shifts of Ras cionin [l]and of the Triterpenoids 5-12.' --
--
Pmoo
H-2 . . . . . . . . . H-3 H-4 . . . . . . . . . H-7 . . . . . . . . . H-8 . . . . . . . . . H-9
. . . . .. .. .
H-11 . . . . . . . . H-12 . . . . . . . . H-13 H-14 . . . . . . . . H-16 . . . . . . . . H-17
.
H-18 . . . . . . . . H-21 . . . . . . . . H-22 . . . . . . . . H-23 H,-25 H,-26 H,-27 H's-28
. . . .. . . . . . . .. . . . . . .. . . . . . .. .
H,-29 . . . . . . . H,-30 . . . . . . . H,-31 . . . . . . . H,-32 . . . . . . . OCOCH,-4 . . . OCOCH,-10 . . OCOCH,-lS . . OCOCH,-21 . .
1 1.48 1.65 1.82 2.00 3.83 3.68 1.38 1.62 1.95 2.24 1.64 1.50 1.62 1.18 1.72 0.74 1.31 2.80 1.39 1.51 3.41 4.97 1.81 2.00 1.27 1.45 0.70 1.12 1.27 4.60 4.89 1.53 1.15 1.20 0.94
6
5 1.49 1.66 1.79 1.98 3.82 3.67 1.36 1.63 1.95 2.25 1.66 1.52 1.68 1.12 1.68 0.83 1.26 2.76 1.36 1.43 3.55 3.82 1.75 1.98 1.38 1.57 0.69 1.12* 1.26** 4.61 4.88 1.51 1.27** 1.11* 0.93
1.59 ndb 1.74 2.02 3.82 3.63 1.43 1.53 1.66 2.63 1.53 1.47 ndb ndb 1.77 0.80 1.26 2.78 1.36 1.46 3.56 3.82 1.74 2.02 1.45 1.69 0.83 1.11* 1.26** 1.48
7
8
9
10
11
12
1.32 1.87 2.13 3.18
1.33 1.87 2.13 3.18
1.32 1.80 2.13 3.20
1.26 1.41 1.75 2.00
1.31 1.80 2.13 3.19
1.29 1.79 2.14* 3.20
-
-
-
4.99
-
-
2.% 1.27 1.58 1.62 2.68 1.42 ndb 1.60 1.33 1.70 0.74 1.45 1.61 1.40 1.74 3.35 4.97 1.76 1.98 1.22 1.60 0.99 1.25 1.31 1.50
3.48 1.41 1.57 1.66 2.66 1.47 1.34* 1.57 1.38* 1.75 0.76 1.47 1.64 1.41 1.73 3.37 4.98 1.75 2.00 1.26 1.41 0.87 1.20** 1.14" 1.50
2.92** ndb ndb 1.79 ndb 1.OO 1.29 1.54 1.29 1.75 0.66 1.23 2.84 1.47 1.60 2.93**
-
2.97 1.36 1.56 1.69 2.67 1.45 ndb 1.62 1.30 1.69 0.83 1.47 1.60 1.39 1.71 3.50 3.82 1.73 2.02 1.37 1.53 0.99 1.25 1.31 1.50
2.95 1.30 1.61 1.67 2.66 1.43 ndb 1.60 ndb 1.74 0.69 1.45 1.64 1.45 1.88 2.89
-
2.97 1.33 1.61 1.67 2.65 1.46 ndb 1.60 1.35 1.74 0.79 1.26 2.78 1.37 1.46 3.55 3.83 1.74 2.03 1.38 1.56 0.98 1.25 1.31 1.50
1.53 1.27** 1.13' 0.96
1.52 1.26 1.14 0.94
1.17 1.27 1.13 0.99
1.20 1.15 1.20 0.97
-
-
-
-
-
-
-
-
-
-
1.%
-
1.90 1.93
1.97
1.95 2.17
1.89 1.93 -
-
1.93
-
-
-
2.09 3.23 1.17 1.80
2.12* 3.23 1.20 1.79 0.93 1.27' 1.311.18
O.%
1.27* 1.30** 1.50
-
-
-
1.24 1.15' 1.18** 1.OO 2.15" 1.98
1.18 1.31** 1.25* 1.12
1.53 1.30" 1.26' 1.08
-
l.%
-
-
-
2.15
2.16"
-
-
1.96
-
% X I , ; B er AMX-500 spectrometer. Chemical shifts referenced to CHCI, at 7.26 ppm. bNd=Not detected. * * * " ~ a l u e swith the same superscripts may be interchanged.
(C,,H@O, requires 472.3552) and showed a 13C-nmrsignal at 6 217.56 that suggested the presence of a C = O group; its 'H- and 13C-nmrspectra are reported in Tables 1 and 2. The 'H-nmr spectrum of 8 was almost identical to that of 7 with the only differences due to the absence of the acetyl group at C-15 that shifted C-15 to 6 72.20 (6 84.11 for 7 ,C-16 to 6 39.25 (6 33.03 for 7,C-29 to 6 30.31 (6 24.73 for 7 ) and, surprisingly, C-14 to 6 55.68 (6 57.95 for 7 ) . All the nmr resonances were confirmed by 2D experiments. In particular, HMBC experiments exhibited a series of 'H-13Clong-range hetero-correlations (see Experimental) that further supported the assignments of all other raspacionin derivatives. 1O-Acetoxy-15-deacetyl-4-oxo-28-hydroraspacionin 191gave C3,HS608,assigned requires 532.3764). The spectral by hreims at mlz 532.3752 {M-HOAc)+ (C32H5206 data were closely related to those of 8 and, in particular, the 'H-nmr resonance at 6 4.97 (H-21; 6 3.82 for S), suggested a structure 9 that was easily confirmed by acetylation of 8. 10-Acetoxy-4-acetyl-15-deacety1-28-hydroraspacionin [lo] exhibited C,,H,O, that was assigned by hreims at mlz 516.3803 EM-2 HOAc}+ (C32HS205 requires 516.3814). The 'H- and 13C-nmrspectra of 10 (Tables 1 and 2) displayed resonances similar to those of 9 but with the ',C-nmr resonance at 6 2 17.30 substituted by a signal
788
Journal of Natural Products
mol. 57, No. 6
at 6 78.76, consistent with the presence of a secondary carbon (C-4) bearing an acetoxy group. The f3-orientation of the substituent at C-4 was suggested by comparison of the nmr data of 10 (C-4 6 78.76, H-4 6 4.99) with those, already reported (2), of 2 (C-21 6 80.80, H-2 16 4.70). Compound 10 is also related to 6,but with adifferent acetylation pattern. In fact, the 'H-nmr resonances of H-4 and H-21 were shifted to 6 4.99 and 4.98, respectively, whereas the deacetylation at C-15 was supported by the diagnostic I3C-nmr values of C-15 (6 72.25), C-16 (6 39.41) and C-29 (6 30.41). lO-Acetoxy-l5deacety1-4,2 1-dioxo-28-hydroraspacionin[ll]possessed the moas determined by hreims at mlz 488.3490 {M-HOAC}' lecular formula C32H5207, (C30H4805 requires 488.3501). The n m r data of 11 suggested a structure closely related to 10 but displaying two carbonyls at C-4 and C-21. It differed from 9 only by the functionalitation at C-21 that shifted H3-32 to 6 1.12 (0.97 for 9) and H-18 to 6 2.89 (3.35 for 9).Theperhydrobenzoxepine halfof 11,bearing the hydroxy group, displayed 'H- and I3C-nmrvalues almost identical to those of the corresponding partial structure in sipholenone A 1131 (12). lO-Hydroxy-4,2 1-dioxo-28-hydroraspacioninE127 exhibited C32H5207 by hreims at mlz488.3482 [M-HOAc]' (C3&4805requires 488.3501). The same functionalization of 11 was observed in 12, but with interchange of the acetoxy and hydroxy groups at carbons 10 and 15. The different functionalization of the oxygenated substituents at C10 and C-15 induced a series of shifts on the vicinal carbons, including a surprising 13Cnmr downfield acetylation effect on C-14 (6 57.93 for 12;6 55.52 for 11).By analogy with 11, the unacetylated unit of 12 was identical to the perhydrobentoxepine moiety of sodwanone A 1141 (16) as confirmed by comparison of nmr data. All raspacionins (7, 8, 9, 11, and 12) containing a ketone moiety displayed a positive cd maximum at ca. 302 nm that suggested an absolute stereochemistry identical to those of the 4-oxo-derivative of raspacionin 117,the 2 1-oxo-derivative of raspacionin A 121, and raspacionin B E31 (3). The same absolute stereochemistry is presumably also possessed by the other raspacionins. EXPERIMENTAL GENERAL EXPERIMENTALPROCEDU.-Ft-ir spectra were recorded with a Biorad FTS-7 instrument. Low-resolution ms were determined on a VG Trio-2000. High-resolution ms were determined on a Kratos MS-50spectrometer. Optical rotations were recorded on a Jasco DIP-370 polarimeter. Cd measurements were carried out on a Jasco J-710 dicograph. Hplc was performed on a Waters apparatus equipped with a differential refractometer. Commercial Si gel (70-230 mesh ASTM) was used for column chromatography. Analytical tlc was carried out using precoated Si gel Merck F,,, plates. lDand 2Dnmrspectrawererecordedat roomtemperaturewithaBrukerAMX-500spectrometer('H, 500.13 MHz; I3C, 125.76 MHz), equipped with a X32 data system. 'H- and "C-nmr chemical shifts were referenced to CHCI,, resonating at 6 7.26 and 77.00 ppm, respectively. The DEFT spectra were obtained using polarization transfer pulses of 135". Two dimensional experiments were performed using standard Bruker microprograms. EXTRACTION AND ISOLATION OF RASPACIONINS.--The sponge &spurzoM acduta was collected by hand in Blanes (northeastern Spain) during December 1991, using scuba in an overhang at a depth of 10-15 m. A voucher specimen is deposited at the Centre d'Estudios Avanzados (Blanes). The Et,O-soluble fraction (1.15 g ) from the Me,CO extract of the fresh sponge (dry wt 12.0 g ) was fractionated on a Si gel Bash column using light petroleum ether with increasing amounts of Et,O as eluent to afford, along with the main metabolite l ( 1 5 8 mg) (tlc, Rf0.45, light petroleum ether-Et,O, 1:l) and a fraction (115 mg) containing a mixture of 2 and 3 (tlc, Rf0.70, light petroleum ether-Et,O, l:l), a more polar fraction (116 mg) (tlc, I?, 0.27, light petroleum ether-Et,O, 3:7) containing a mixture of the new triterpenoids 5 1 2 . This fraction was chromatographed by hplc using a Spherisorb Silica S5W column (25 cmX 10 mm, particle size 5 pm, flow rate 2.5 ml/min-') and n-hexane-EtOAc (7:3) as eluent, yielding seven main fractions: A (4.8 mg), B (17.0 mg), C (11.0 mg), D (6.0 mg), E (13.0 mg), F (10.0 mg), and G (6.8 mg). Each fraction was further purified by hplc using a Spherisorb 5 Si1column (25 cmX4.6 mm, particle size 5 pm) and different eluents. In particular, elution ofA with CHCI, (flow rate 1.0 ml/min-') yielded 3.1 mg of 1 1 ; elution of B with n-
June 19941
Cimino et al. : Triterpenoids from Raspasiona
789
hexane-i-PrOH (9223)(flow rate 1.0 mYmin-') yielded 5.7 mg of 9 and 3.5 mg of 7;elution of C with nhexane-i-PrOH (92%)(flow rate 1.0 ml/min-') yielded 2.7 mg of 5 ; elutionofD with CHCI, (flow rate 1.0 mumin-') yielded 3.1 mg of 12;elution of E with CHCI, (flow rate 1.0 mumin-') yielded 2.5 mg of 10; elution of F with n-hexane-i-PrOH (9:l) (flow rate 1.5 mumin-') yielded 2.6 mg of 6; elution of G with n-hexane-i-PrOH (91)(flow rate 1.5 mumin-') yielded 2.7 mg of 8. ~THANOLYSIS OF 1 TO GIVE 5.-Raspacionin [l](2.5 mg) was treated with 1.0 ml of a solution of KOH (3% in MeOH) stirring at room temperature. The reaction was monitored by tlc (light petroleum ether-Et,O, 4:6) and stopped after 2 h, when the starting product spot disappeared. The usual work up gave 3.0 mg of a residue that was purified on Si gel contained in a Pasteur pipette using petroleum ether-Et,O (3:7) as eluent, to give 2.0 mg of pure compound 5.
ACETYLATION OF 8 TO GIVE 9.-A few drops of Ac,O were added to a solution of 8 (1.4 mg) in dry pyridine (500 ml) and the reaction mixture was kept at room temperature overnight. After removal of the solvent in uacuo, the usual work up gave 1.O mg of pure compound 9. Raspacionin [l].--Cd ( ~ = 5 . 7 8 X l O -M; ~ EtOH) 20" [81206M) +3469. 21 -Deucetyl-ra~pacionin[5].-Amorphouspowder: [aI2'D -49. lo(c=0.25,CHCI,); cd ( ~ 5 . 2 0 X lo-, M; EtOH) 20" [8],,,,,+2677; ir u max(1iquid film, CHCI,) 2974,2934,1730,1712 cm-'; eims mlz 474 [M-C,H,O,]+ (5), 416 [M-C,H,0,-C3H,0]+ (5), 398 [M-C,H,O,-C,H,O-H,O~+ (2), 372 (lo), 314 (15); hreims m/z 474.3698 [M-C,H,O,]+ (C,d-IH,,O,requires 474.3709); 'H- and ',C-nmr data, see Tables 1 and 2. 10-Acetoq-21-&etyI-28-bydtwasparionin [6].-Amorphouspowder: [ a ] " ~ -27.7"(c=O.26,CHCI3); cd (c=4.86X M; EtOH) 20" [81210.60 -80.76; ir u rnax (liquid film, CHCI,) 2973,2933,2866, 1727 cm-'; eimsmlz474 [M-2C2H40,]+ (3),416 [M-2C,H402- C,H,O]+ (5), 314(7); hreimsmlz474.3684 (C,,,",,O, requires 474.3709); 'H- and I3C-nmr data, see Tables 1 and 2. IO-Acetoq-21-~etyl-4-oxo-28-bydroraspacionin m.-Amorphous powder: [a]''~-38.5" (c=0.37, CHCI,); cd (~=4.17X M; EtOH) 20' [8]zw,50 f9472, [O],2,o +8897; ir u rnax (liquid film,CHCI,) 2972,2940,2867,1718 cm-';eimsm/z 514 [M-C,H40,-H,0]+ (0.15), 472 [M-2C,H40,1' (13), 414 [M-ZC,H,O,-C,H,O]+ (4), 386 (2); hreims mlz 5 14.3645 [M-C,H40,-H,01+ (C,,H,,O, requires 514.3658); 'H- and "C-nmr data, see Tables 1 and 2. IO-Acetaay-l~,21-dideacetyl-4-oxo-28-~d~~~imin[8~.-Amorphouspowder: [aI2'~ -9.5"(c=0.36, CHCI,); cd (~=7.27X M; EtOH) 20" [81,,,,+1200, [8],, ',+ 1109; ir u rnax (liquid film, CHCI,) 2922,2852, 1716 cm-'; eims mlz 472 [M-C,H,O,-H,OIC (l), 432 [M-C,H,O,-C,H,OI+ (2), 414 [M-C,H,O,-C,H,O-H,O]+ (l), 372 (3); hreims mlz 472.3535 (C,d-I,,O, requires 472.3552); 'H- and 13C-nmrdata, see Tables 1 and 2; HMBC data (]=lo Hz) 6 42.14 (C-1) 0.99 (H,-25), 2.13 (H-3); 40.14 (C-2) 0.99 (H,-25), 2.13 (H-3), 2.97 (H-7), 3.18 (H-3); 35.02 (C-3) 1.87 (H-2); 217.56 ( C 4 ) 3.18 (H-3); 82.65 (C-5) 1.25 (H,-26), 1.31 (H3-27),2.13(H-3),2.97 (H-7);8O.68(C-7)0.99(H3-25), 1.87(H-2), 2.67 (H-9); 35.24(C-9) 1.50(H3-28);86.27 (C-10) 1.50(H3-28),2.67 (H-9); 55.68(C-11)0.99(H3-25), 1.50 (H,-28), 1.69 (H-9 and/or H-13), 2.67 (H-9); 27.96 (C-12) 0.83 (H-14), 1.45 (H-11); 28.87 (C-13) 0.83 (H-14); 55.68 (C-14) 0.97 (H,-32), 1.17 (H,-29), 1.60 (H-16); 72.20, (C-15) 1.17 (H,-29), 1.60 (H-16), 1.69 (H-13); 39.25 (C-16) 1.17 (H,-29); 76.25 (C-18)0.97 (H,-32), 1.39 (H-17), 1.60 (H-16); 77.76 (C20) 1.13(H3-31),1.27(H~-30),3.50(H-18~~77.17(C-21~1.13(H~-31~, 1.27(H3-30), 1.73(H-22);25.09 (C-22) 1.53 (H-23), 3.82 (H-21); 34.12 (C-23)0.83 (H-14), 0.97 (H,-32), 2.02 (H-22), 3.50 (H-18), 3.82 (H-21);42.55 (C-24)0.83 (H-14),0.97 (H,-32), 1.69(H-13); 12.49(C-25) 2.97 (H-7); 26.42 (C-26) 1.31 (H,-27); 20.45 (C-27) 1.25 (H3-26);30.31 (C-29) 0.83 (H-14); 21.31 (C-30) 1.13 (H3-31); 29.00 (C-31) 1.27 (H,-30), 3.82 (H-21); 12.93 (C-32) 0.83 (H-14), 1.37 (H-23), 3.50 (H-18). I 0-Acetoxy- 15 -deucetyld -0xo-28-bydrora~pacianin I91.-Amorphous powder: [a12'D - 18.2' (e= 0.50, CHCI,); cd (c=5.63x lo-, M; EtOH) 20' [81,10,ro +9288, [8~30,M)+8689; ir u max (liquid film, CHCI,) 2973, 2940, 2862, 1721 cm-'; eims mlz 532 [M-C,H,O,I+ (l), 472 [M-2C,H4O,1+ (21, 414 [M-2C,H,0,-C,H60]+ (1); hreims mlz 532.3752, (C,,H,,O, requires 532.3764); 'H- and "C-nmr data, see Tables 1 and 2. I 0-Acetaaydayl-I 5&tyl-28-bydtwa~acimin [lOI.-Amorphous powder: [a]"~ - 35. 1" ( ~ 0 . 0 5 , CHCI,);cd(c=4.36X10-4M; EtOH)20°[8]206,ra+1820;irumax(1iquid film,CHC1,)2971,2938, 2865, 1726 cm-'; eims mlz 516 [M-ZC,H,O,I+ (l), 498 [M-2C,H40,-H,01+ (l), 432 (3), 414 (4), 372 (3); hreims mlz 516.3803 (C32H1201requires 516.3814); 'H- and "C-nmr data, see Tables 1 and 2.
IO-Aceto.yy-l5-&etyl-4,21 -dioxo-28-bydroraspacioninEll].-Amorphous powder: [a]"D - 36.1' (c=0.1,CHCI,);cd(c=6.08X10-4M; EtOH)20°~8~,,140+10420,[8],,,,,+10210; irumax(liquidfilm, CHCI,) 2971,2937,2869,1704 cm-'; eims mlz 488 [M-C,H,O,]+ (2), 430 [M-C,H,O,-C,H,O]+ (2),
790 412 [M-C2H4O2-C,&0-H20]+ nmr data, see Tables 1 and 2 .
Journal of Natural Products
Wol. 57, No. 6
(2); hreims mlz 488.3490 (C&I,O,
requires 488.3501); 'H- and I3C-
IO-Hydrary-4,21dioxo-28-hydro~~n[12].--Amorphouspowder: [U]"D -5.9"(~=0.28,CHCI,); cd(c=6.81 X 10-4M,EtOH)2O0[Q,,,,,+6500, [01,2,,o+6569; irvrnax(liquidfilrn,CHCI,) 2974,2936, 2863, 1707 crn-'; eirns m/z 488 [M-C2H,021C (2), 470 IM-C2H402-H207f (2), 430 [M-C2H,02-C,H60]f (2), 412 ~M-C2H402-C,H60-H,01+ (2); hreims m/z 488.3482 (C&4801 requires 488.3501); 'H- and "C-nmr data, see Tables 1 and 2. ACKNOWLEDGMENTS The authors are grateful to Mr. F. Castellucciofor hplc assistance and to Mr. R. Turco for graphic work. We offer particular thanks to Mr. A. Crispino and Mr. G. Scognamiglio for technical support. The nmr spectra were recorded at the ICMIB-Nmr Service. Mass spectra were provided by the Servizio di Spettrometria di Massa. Staffs of both services are gratefully acknowledged. This work was supported by EEC project Sciences and Technologies Marines Mast 11, Contract MAS2-CT 91-0004. LITERATURE CITED 1. 2.
3. 4.
5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16.
G. Cimino, A. Crispino, C.A. Mattia, L. Mazzarella, R. Puliti, E. Trivellone, and M. Uriz, Tetrahedm Letr., 31,6565 (1990). G. Cimino, A. Crispino, R. de A. Epifanio, A. Madaio, C.A. Mattia, L. Matzarella, R. Puliti, E. Trivellone, and M. Uriz, Tetrahedron,48,9013 (1992). G. Cirnino, A. Crispino, A. Madaio, and E. Trivellone,J. Nat. Prod, 56, 534 (1993). G. Cimino, R. de A. Epifanio,A. Madaio, R. Puliti, and E. TrivelloneJ. Nar. Prod., 56,1622 (1993). J.A. Dale and H.S. Mosher,]. Am. C h .Soc., 95, 512 (1973). G.R. Sullivan, J.A. Dale, and H.S. Mosher,]. Org. C h . ,38,2143 (1973). T. Kusumi, I. Ohtani, Y. Inouye, and H. Kakisawa, Tetrahedm k t t . , 29,4731 (1988). I. Ohtani, T. Kusumi, O.M. Ishitsuka, and H. Kakisawa, Tetruhedm Len., 30,3147 (1989). I. Ohtani, T. Kusumi, Y. Kashman,and H. Kakisawa,]. Org. Chem., 56,1296 (1991). I. Ohtani, T. Kusumi, Y. Kashman,and H. Kakisawa,]. Am. C h .Sw., 113,4092 (1991). U. Shrnueli, S. Carmeli, A. Groweiss, and Y . Kashman,Tetrahedm Lett., 22,709 (1981). S . Carmeli and Y. Kashman,]. Org. C h . ,48, 3517 (1983). S. Carmeli, Y. Laya, and Y . Kashman,Tetrahedron Lett., 24, 3673 (1983). S. Carmeli and Y. Kashman,]. Org. C h . ,51,784 (1986). S. Carmeli and Y. Kashman,Map. Reson. C h . ,24,332 (1986). A. Rudi, I. Goldberg, Z. Stein, Y. Benayahu, M. Schleyer, and Y. Kashman, Tetrahedm Le#., 34, 2943 (1993).
Reseived 30 Dcc&
I993
